Watch the following videos and answer the questions ## Private, Package, Protected, Public (28) * What are APIs? * Note the class diagrams. What do - + # mean? * What are unit tests? * Why do we use getters and setters? * What does immutable mean? * What is a package? <iframe width="560" height="315" src="https://www.youtube.com/embed/eQCXrNBD0aQ" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe> <https://www.youtube.com/watch?v=eQCXrNBD0aQ> ## Inheritance (29) * How many parents can a Java class have? * How do you show inheritance on a class diagram? * How can a child class access a private variable in the parent class? * Which class are all classes in Java inherited from? <iframe width="560" height="315" src="https://www.youtube.com/embed/TAzmgIrt3Fw" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe> <https://www.youtube.com/watch?v=TAzmgIrt3Fw> ## Override a Method (30) * What is an override? * How can you stop a method being overridden? * Is the @Override annotation necessary? * What does super do? * What is shadowing? <iframe width="560" height="315" src="https://www.youtube.com/embed/x3lcQrfOrP0" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe> <https://www.youtube.com/watch?v=x3lcQrfOrP0> ## Polymorphism (31) * What is polymorphism? * Give examples of polymorphism * What are the three concepts of OOP? <iframe width="560" height="315" src="https://www.youtube.com/embed/SwEzCBM7n-Q" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe> <https://www.youtube.com/watch?v=SwEzCBM7n-Q>